This is the general area a striker in a 7v7 formation should position themselves. The striker should try to align themselves with the ball when it is on the defensive half of the field in order to provide a target for a pass or clearance from a teammate. This means moving side to side, not just running towards the goal they are attacking. Generally the striker should try be in the middle of the field in order to limit the amount of running side to side in order to conserve energy for an attack.
In a 7v7 formation, when the striker receives the ball, unless on a breakaway, should attempt to possess the ball and pass it out wide into the space for an outside midfielder to run onto, or look to play it back to the center mid in order for them to possess and pass. Typically, the most successful off-the-ball-run for a striker is a diagonal one into space. This will normally do one of two things: 1) Pull defenders away from their normal positions 2) Allow the striker to run into space while remaining on-side.
7v7 is tougher for a striker than in other formations as they simply can't dribble by the defense by themselves and they may not have other players in close support. The striker should cherish the ball, but if they see an opportunity to take a shot, do it with confidence.